body {
  margin: 0;
}
#game {
  display: flex;
  justify-content: center;
  margin-top: 100px;
}
#game #snake {
  display: block;
  background-color: black;
}
#game .tip {
  width: 200px;
  background-color: lightblue;
  border: 1px solid;
}
#game .tip p {
  margin-left: 50px;
}
#game .tip p.operate {
  color: green;
}

